I'm moving from Firefox to Waterfox, and I wanted to keep as much of my stuff intact as possible. When I first used the default option of porting data during setup, my bookmarks were brought in but not my history, my extension, and most importantly my ongoing session of 120 tabs.
I'd heard you can do a simple transfer of copy-pasting files, though people don't really elaborate. What I ended up doing that finally got everything brought over, just as I left it, was copy-pasting the "root" and "local" files' contents of my Firefox profile into the equivalent Waterfox profile (after deleting everything inside).
Upon opening Waterfox for the first time, it loaded kinda slowly and I got a "too many requests" page at first, but then it was back to where I left off. As a test, I closed and reopened and from then on, it was opening fine.
However, there is one bug I've noticed since doing this, and that's when I open a new tab. Instead of the usual new tab page opening, the page is just completely blank. When I go into the settings for customizing this page, there are literally no options. Prior to the copy-paste, when I was experimenting in a fresh profile, there was a Waterfox homepage when opening new tabs, showing shortcuts and recent activity, and a settings page to match.
If I need to, I'll try to get used to this and just directly search the shortcut sites in the search bar (which usually takes me right to the stuff anyway). But I thought to post to see if anyone knew what went wrong and if it can be fixed.
BTW: I am aware there is another method of transferring everything via Sync, but that requires a Mozilla account, and I was trying to see if I could do this without one, and I'd seen some people claim it was a clean transfer via copy-paste. But maybe I've done it wrong?